/* eslint-disable ts/no-namespace */
/*
 * QR Code generator library (TypeScript)
 *
 * Copyright (c) Project Nayuki. (MIT License)
 * https://www.nayuki.io/page/qr-code-generator-library
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy of
 * this software and associated documentation files (the "Software"), to deal in
 * the Software without restriction, including without limitation the rights to
 * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
 * the Software, and to permit persons to whom the Software is furnished to do so,
 * subject to the following conditions:
 * - The above copyright notice and this permission notice shall be included in
 *   all copies or substantial portions of the Software.
 * - The Software is provided "as is", without warranty of any kind, express or
 *   implied, including but not limited to the warranties of merchantability,
 *   fitness for a particular purpose and noninfringement. In no event shall the
 *   authors or copyright holders be liable for any claim, damages or other
 *   liability, whether in an action of contract, tort or otherwise, arising from,
 *   out of or in connection with the Software or the use or other dealings in the
 *   Software.
 */

'use strict'

namespace qrcodegen {
  type bit = number
  type byte = number
  type int = number

  /* ---- QR Code symbol class ---- */

  /*
   * A QR Code symbol, which is a type of two-dimension barcode.
   * Invented by Denso Wave and described in the ISO/IEC 18004 standard.
   * Instances of this class represent an immutable square grid of dark and light cells.
   * The class provides static factory functions to create a QR Code from text or binary data.
   * The class covers the QR Code Model 2 specification, supporting all versions (sizes)
   * from 1 to 40, all 4 error correction levels, and 4 character encoding modes.
   *
   * Ways to create a QR Code object:
   * - High level: Take the payload data and call QrCode.encodeText() or QrCode.encodeBinary().
   * - Mid level: Custom-make the list of segments and call QrCode.encodeSegments().
   * - Low level: Custom-make the array of data codeword bytes (including
   *   segment headers and final padding, excluding error correction codewords),
   *   supply the appropriate version number, and call the QrCode() constructor.
   * (Note that all ways require supplying the desired error correction level.)
   */
  export class QrCode {
    /* -- Static factory functions (high level) -- */

    // Returns a QR Code representing the given Unicode text string at the given error correction level.
    // As a conservative upper bound, this function is guaranteed to succeed for strings that have 738 or fewer
    // Unicode code points (not UTF-16 code units) if the low error correction level is used. The smallest possible
    // QR Code version is automatically chosen for the output. The ECC level of the result may be higher than the
    // ecl argument if it can be done without increasing the version.
    public static encodeText(text: string, ecl: QrCode.Ecc): QrCode {
      const segs: QrSegment[] = qrcodegen.QrSegment.makeSegments(text)
      return QrCode.encodeSegments(segs, ecl)
    }

    // Returns a QR Code representing the given binary data at the given error correction level.
    // This function always encodes using the binary segment mode, not any text mode. The maximum number of
    // bytes allowed is 2953. The smallest possible QR Code version is automatically chosen for the output.
    // The ECC level of the result may be higher than the ecl argument if it can be done without increasing the version.
    public static encodeBinary(
      data: Readonly<byte[]>,
      ecl: QrCode.Ecc
    ): QrCode {
      const seg: QrSegment = qrcodegen.QrSegment.makeBytes(data)
      return QrCode.encodeSegments([seg], ecl)
    }

    /* -- Static factory functions (mid level) -- */

    // Returns a QR Code representing the given segments with the given encoding parameters.
    // The smallest possible QR Code version within the given range is automatically
    // chosen for the output. Iff boostEcl is true, then the ECC level of the result
    // may be higher than the ecl argument if it can be done without increasing the
    // version. The mask number is either between 0 to 7 (inclusive) to force that
    // mask, or -1 to automatically choose an appropriate mask (which may be slow).
    // This function allows the user to create a custom sequence of segments that switches
    // between modes (such as alphanumeric and byte) to encode text in less space.
    // This is a mid-level API; the high-level API is encodeText() and encodeBinary().
    public static encodeSegments(
      segs: Readonly<QrSegment[]>,
      ecl: QrCode.Ecc,
      minVersion: int = 1,
      maxVersion: int = 40,
      mask: int = -1,
      boostEcl: boolean = true
    ): QrCode {
      if (
        !(
          QrCode.MIN_VERSION <= minVersion
          && minVersion <= maxVersion
          && maxVersion <= QrCode.MAX_VERSION
        )
        || mask < -1
        || mask > 7
      ) {
        throw new RangeError('Invalid value')
      }

      // Find the minimal version number to use
      let version: int
      let dataUsedBits: int
      for (version = minVersion; ; version++) {
        const dataCapacityBits: int
          = QrCode.getNumDataCodewords(version, ecl) * 8 // Number of data bits available
        const usedBits: number = QrSegment.getTotalBits(segs, version)
        if (usedBits <= dataCapacityBits) {
          dataUsedBits = usedBits
          break // This version number is found to be suitable
        }
        if (version >= maxVersion) {
          // All versions in the range could not fit the given data
          throw new RangeError('Data too long')
        }
      }

      // Increase the error correction level while the data still fits in the current version number
      for (const newEcl of [
        QrCode.Ecc.MEDIUM,
        QrCode.Ecc.QUARTILE,
        QrCode.Ecc.HIGH
      ]) {
        // From low to high
        if (
          boostEcl
          && dataUsedBits <= QrCode.getNumDataCodewords(version, newEcl) * 8
        ) {
          ecl = newEcl
        }
      }

      // Concatenate all segments to create the data bit string
      const bb: bit[] = []
      for (const seg of segs) {
        appendBits(seg.mode.modeBits, 4, bb)
        appendBits(seg.numChars, seg.mode.numCharCountBits(version), bb)
        for (const b of seg.getData()) {
          bb.push(b)
        }
      }

      // Add terminator and pad up to a byte if applicable
      const dataCapacityBits: int = QrCode.getNumDataCodewords(version, ecl) * 8
      appendBits(0, Math.min(4, dataCapacityBits - bb.length), bb)
      appendBits(0, (8 - (bb.length % 8)) % 8, bb)

      // Pad with alternating bytes until data capacity is reached
      for (
        let padByte = 0xEC;
        bb.length < dataCapacityBits;
        padByte ^= 0xEC ^ 0x11
      ) {
        appendBits(padByte, 8, bb)
      }

      // Pack bits into bytes in big endian
      const dataCodewords: byte[] = []
      while (dataCodewords.length * 8 < bb.length) {
        dataCodewords.push(0)
      }
      bb.forEach(
        (b: bit, i: int) => (dataCodewords[i >>> 3] |= b << (7 - (i & 7)))
      )

      // Create the QR Code object
      return new QrCode(version, ecl, dataCodewords, mask)
    }

    /* -- Fields -- */

    // The width and height of this QR Code, measured in modules, between
    // 21 and 177 (inclusive). This is equal to version * 4 + 17.
    public readonly size: int

    // The index of the mask pattern used in this QR Code, which is between 0 and 7 (inclusive).
    // Even if a QR Code is created with automatic masking requested (mask = -1),
    // the resulting object still has a mask value between 0 and 7.
    public readonly mask: int

    // The modules of this QR Code (false = light, true = dark).
    // Immutable after constructor finishes. Accessed through getModule().
    private readonly modules: boolean[][] = []

    // Indicates function modules that are not subjected to masking. Discarded when constructor finishes.
    private readonly isFunction: boolean[][] = []

    /* -- Constructor (low level) and fields -- */

    // Creates a new QR Code with the given version number,
    // error correction level, data codeword bytes, and mask number.
    // This is a low-level API that most users should not use directly.
    // A mid-level API is the encodeSegments() function.
    public constructor(
      // The version number of this QR Code, which is between 1 and 40 (inclusive).
      // This determines the size of this barcode.
      public readonly version: int,

      // The error correction level used in this QR Code.
      public readonly errorCorrectionLevel: QrCode.Ecc,

      dataCodewords: Readonly<byte[]>,

      msk: int
    ) {
      // Check scalar arguments
      if (version < QrCode.MIN_VERSION || version > QrCode.MAX_VERSION) {
        throw new RangeError('Version value out of range')
      }
      if (msk < -1 || msk > 7) {
        throw new RangeError('Mask value out of range')
      }
      this.size = version * 4 + 17

      // Initialize both grids to be size*size arrays of Boolean false
      const row: boolean[] = []
      for (let i = 0; i < this.size; i++) {
        row.push(false)
      }
      for (let i = 0; i < this.size; i++) {
        this.modules.push(row.slice()) // Initially all light
        this.isFunction.push(row.slice())
      }

      // Compute ECC, draw modules
      this.drawFunctionPatterns()
      const allCodewords: byte[] = this.addEccAndInterleave(dataCodewords)
      this.drawCodewords(allCodewords)

      // Do masking
      if (msk === -1) {
        // Automatically choose best mask
        let minPenalty: int = 1000000000
        for (let i = 0; i < 8; i++) {
          this.applyMask(i)
          this.drawFormatBits(i)
          const penalty: int = this.getPenaltyScore()
          if (penalty < minPenalty) {
            msk = i
            minPenalty = penalty
          }
          this.applyMask(i) // Undoes the mask due to XOR
        }
      }
      this.mask = msk
      this.applyMask(msk) // Apply the final choice of mask
      this.drawFormatBits(msk) // Overwrite old format bits

      this.isFunction = []
    }

    /* -- Accessor methods -- */

    // Returns the color of the module (pixel) at the given coordinates, which is false
    // for light or true for dark. The top left corner has the coordinates (x=0, y=0).
    // If the given coordinates are out of bounds, then false (light) is returned.
    public getModule(x: int, y: int): boolean {
      return (
        x >= 0 && x < this.size && y >= 0 && y < this.size && this.modules[y][x]
      )
    }

    // Modified to expose modules for easy access
    public getModules(): boolean[][] {
      return this.modules
    }

    /* -- Private helper methods for constructor: Drawing function modules -- */

    // Reads this object's version field, and draws and marks all function modules.
    private drawFunctionPatterns(): void {
      // Draw horizontal and vertical timing patterns
      for (let i = 0; i < this.size; i++) {
        this.setFunctionModule(6, i, i % 2 === 0)
        this.setFunctionModule(i, 6, i % 2 === 0)
      }

      // Draw 3 finder patterns (all corners except bottom right; overwrites some timing modules)
      this.drawFinderPattern(3, 3)
      this.drawFinderPattern(this.size - 4, 3)
      this.drawFinderPattern(3, this.size - 4)

      // Draw numerous alignment patterns
      const alignPatPos: int[] = this.getAlignmentPatternPositions()
      const numAlign: int = alignPatPos.length
      for (let i = 0; i < numAlign; i++) {
        for (let j = 0; j < numAlign; j++) {
          // Don't draw on the three finder corners
          if (
            !(
              (i === 0 && j === 0)
              || (i === 0 && j === numAlign - 1)
              || (i === numAlign - 1 && j === 0)
            )
          ) {
            this.drawAlignmentPattern(alignPatPos[i], alignPatPos[j])
          }
        }
      }

      // Draw configuration data
      this.drawFormatBits(0) // Dummy mask value; overwritten later in the constructor
      this.drawVersion()
    }

    // Draws two copies of the format bits (with its own error correction code)
    // based on the given mask and this object's error correction level field.
    private drawFormatBits(mask: int): void {
      // Calculate error correction code and pack bits
      const data: int = (this.errorCorrectionLevel.formatBits << 3) | mask // errCorrLvl is uint2, mask is uint3
      let rem: int = data
      for (let i = 0; i < 10; i++) {
        rem = (rem << 1) ^ ((rem >>> 9) * 0x537)
      }
      const bits = ((data << 10) | rem) ^ 0x5412 // uint15

      // Draw first copy
      for (let i = 0; i <= 5; i++) {
        this.setFunctionModule(8, i, getBit(bits, i))
      }
      this.setFunctionModule(8, 7, getBit(bits, 6))
      this.setFunctionModule(8, 8, getBit(bits, 7))
      this.setFunctionModule(7, 8, getBit(bits, 8))
      for (let i = 9; i < 15; i++) {
        this.setFunctionModule(14 - i, 8, getBit(bits, i))
      }

      // Draw second copy
      for (let i = 0; i < 8; i++) {
        this.setFunctionModule(this.size - 1 - i, 8, getBit(bits, i))
      }
      for (let i = 8; i < 15; i++) {
        this.setFunctionModule(8, this.size - 15 + i, getBit(bits, i))
      }
      this.setFunctionModule(8, this.size - 8, true) // Always dark
    }

    // Draws two copies of the version bits (with its own error correction code),
    // based on this object's version field, iff 7 <= version <= 40.
    private drawVersion(): void {
      if (this.version < 7) {
        return
      }

      // Calculate error correction code and pack bits
      let rem: int = this.version // version is uint6, in the range [7, 40]
      for (let i = 0; i < 12; i++) {
        rem = (rem << 1) ^ ((rem >>> 11) * 0x1F25)
      }
      const bits: int = (this.version << 12) | rem // uint18

      // Draw two copies
      for (let i = 0; i < 18; i++) {
        const color: boolean = getBit(bits, i)
        const a: int = this.size - 11 + (i % 3)
        const b: int = Math.floor(i / 3)
        this.setFunctionModule(a, b, color)
        this.setFunctionModule(b, a, color)
      }
    }

    // Draws a 9*9 finder pattern including the border separator,
    // with the center module at (x, y). Modules can be out of bounds.
    private drawFinderPattern(x: int, y: int): void {
      for (let dy = -4; dy <= 4; dy++) {
        for (let dx = -4; dx <= 4; dx++) {
          const dist: int = Math.max(Math.abs(dx), Math.abs(dy)) // Chebyshev/infinity norm
          const xx: int = x + dx
          const yy: int = y + dy
          if (xx >= 0 && xx < this.size && yy >= 0 && yy < this.size) {
            this.setFunctionModule(xx, yy, dist !== 2 && dist !== 4)
          }
        }
      }
    }

    // Draws a 5*5 alignment pattern, with the center module
    // at (x, y). All modules must be in bounds.
    private drawAlignmentPattern(x: int, y: int): void {
      for (let dy = -2; dy <= 2; dy++) {
        for (let dx = -2; dx <= 2; dx++) {
          this.setFunctionModule(
            x + dx,
            y + dy,
            Math.max(Math.abs(dx), Math.abs(dy)) !== 1
          )
        }
      }
    }

    // Sets the color of a module and marks it as a function module.
    // Only used by the constructor. Coordinates must be in bounds.
    private setFunctionModule(x: int, y: int, isDark: boolean): void {
      this.modules[y][x] = isDark
      this.isFunction[y][x] = true
    }

    /* -- Private helper methods for constructor: Codewords and masking -- */

    // Returns a new byte string representing the given data with the appropriate error correction
    // codewords appended to it, based on this object's version and error correction level.
    private addEccAndInterleave(data: Readonly<byte[]>): byte[] {
      const ver: int = this.version
      const ecl: QrCode.Ecc = this.errorCorrectionLevel
      if (data.length !== QrCode.getNumDataCodewords(ver, ecl)) {
        throw new RangeError('Invalid argument')
      }

      // Calculate parameter numbers
      const numBlocks: int
        = QrCode.NUM_ERROR_CORRECTION_BLOCKS[ecl.ordinal][ver]
      const blockEccLen: int = QrCode.ECC_CODEWORDS_PER_BLOCK[ecl.ordinal][ver]
      const rawCodewords: int = Math.floor(QrCode.getNumRawDataModules(ver) / 8)
      const numShortBlocks: int = numBlocks - (rawCodewords % numBlocks)
      const shortBlockLen: int = Math.floor(rawCodewords / numBlocks)

      // Split data into blocks and append ECC to each block
      const blocks: byte[][] = []
      const rsDiv: byte[] = QrCode.reedSolomonComputeDivisor(blockEccLen)
      for (let i = 0, k = 0; i < numBlocks; i++) {
        const dat: byte[] = data.slice(
          k,
          k + shortBlockLen - blockEccLen + (i < numShortBlocks ? 0 : 1)
        )
        k += dat.length
        const ecc: byte[] = QrCode.reedSolomonComputeRemainder(dat, rsDiv)
        if (i < numShortBlocks) {
          dat.push(0)
        }
        blocks.push(dat.concat(ecc))
      }

      // Interleave (not concatenate) the bytes from every block into a single sequence
      const result: byte[] = []
      for (let i = 0; i < blocks[0].length; i++) {
        blocks.forEach((block, j) => {
          // Skip the padding byte in short blocks
          if (i !== shortBlockLen - blockEccLen || j >= numShortBlocks) {
            result.push(block[i])
          }
        })
      }
      return result
    }

    // Draws the given sequence of 8-bit codewords (data and error correction) onto the entire
    // data area of this QR Code. Function modules need to be marked off before this is called.
    private drawCodewords(data: Readonly<byte[]>): void {
      if (
        data.length
        !== Math.floor(QrCode.getNumRawDataModules(this.version) / 8)
      ) {
        throw new RangeError('Invalid argument')
      }
      let i: int = 0 // Bit index into the data
      // Do the funny zigzag scan
      for (let right = this.size - 1; right >= 1; right -= 2) {
        // Index of right column in each column pair
        if (right === 6) {
          right = 5
        }
        for (let vert = 0; vert < this.size; vert++) {
          // Vertical counter
          for (let j = 0; j < 2; j++) {
            const x: int = right - j // Actual x coordinate
            const upward: boolean = ((right + 1) & 2) === 0
            const y: int = upward ? this.size - 1 - vert : vert // Actual y coordinate
            if (!this.isFunction[y][x] && i < data.length * 8) {
              this.modules[y][x] = getBit(data[i >>> 3], 7 - (i & 7))
              i++
            }
            // If this QR Code has any remainder bits (0 to 7), they were assigned as
            // 0/false/light by the constructor and are left unchanged by this method
          }
        }
      }
    }

    // XORs the codeword modules in this QR Code with the given mask pattern.
    // The function modules must be marked and the codeword bits must be drawn
    // before masking. Due to the arithmetic of XOR, calling applyMask() with
    // the same mask value a second time will undo the mask. A final well-formed
    // QR Code needs exactly one (not zero, two, etc.) mask applied.
    private applyMask(mask: int): void {
      if (mask < 0 || mask > 7) {
        throw new RangeError('Mask value out of range')
      }
      for (let y = 0; y < this.size; y++) {
        for (let x = 0; x < this.size; x++) {
          let invert: boolean
          switch (mask) {
            case 0:
              invert = (x + y) % 2 === 0
              break
            case 1:
              invert = y % 2 === 0
              break
            case 2:
              invert = x % 3 === 0
              break
            case 3:
              invert = (x + y) % 3 === 0
              break
            case 4:
              invert = (Math.floor(x / 3) + Math.floor(y / 2)) % 2 === 0
              break
            case 5:
              invert = ((x * y) % 2) + ((x * y) % 3) === 0
              break
            case 6:
              invert = (((x * y) % 2) + ((x * y) % 3)) % 2 === 0
              break
            case 7:
              invert = (((x + y) % 2) + ((x * y) % 3)) % 2 === 0
              break
            default:
              throw new Error('Unreachable')
          }
          if (!this.isFunction[y][x] && invert) {
            this.modules[y][x] = !this.modules[y][x]
          }
        }
      }
    }

    // Calculates and returns the penalty score based on state of this QR Code's current modules.
    // This is used by the automatic mask choice algorithm to find the mask pattern that yields the lowest score.
    private getPenaltyScore(): int {
      let result: int = 0

      // Adjacent modules in row having same color, and finder-like patterns
      for (let y = 0; y < this.size; y++) {
        let runColor = false
        let runX = 0
        const runHistory = [0, 0, 0, 0, 0, 0, 0]
        for (let x = 0; x < this.size; x++) {
          if (this.modules[y][x] === runColor) {
            runX++
            if (runX === 5) {
              result += QrCode.PENALTY_N1
            }
            else if (runX > 5) {
              result++
            }
          }
          else {
            this.finderPenaltyAddHistory(runX, runHistory)
            if (!runColor) {
              result
                += this.finderPenaltyCountPatterns(runHistory) * QrCode.PENALTY_N3
            }
            runColor = this.modules[y][x]
            runX = 1
          }
        }
        result
          += this.finderPenaltyTerminateAndCount(runColor, runX, runHistory)
          * QrCode.PENALTY_N3
      }
      // Adjacent modules in column having same color, and finder-like patterns
      for (let x = 0; x < this.size; x++) {
        let runColor = false
        let runY = 0
        const runHistory = [0, 0, 0, 0, 0, 0, 0]
        for (let y = 0; y < this.size; y++) {
          if (this.modules[y][x] === runColor) {
            runY++
            if (runY === 5) {
              result += QrCode.PENALTY_N1
            }
            else if (runY > 5) {
              result++
            }
          }
          else {
            this.finderPenaltyAddHistory(runY, runHistory)
            if (!runColor) {
              result
                += this.finderPenaltyCountPatterns(runHistory) * QrCode.PENALTY_N3
            }
            runColor = this.modules[y][x]
            runY = 1
          }
        }
        result
          += this.finderPenaltyTerminateAndCount(runColor, runY, runHistory)
          * QrCode.PENALTY_N3
      }

      // 2*2 blocks of modules having same color
      for (let y = 0; y < this.size - 1; y++) {
        for (let x = 0; x < this.size - 1; x++) {
          const color: boolean = this.modules[y][x]
          if (
            color === this.modules[y][x + 1]
            && color === this.modules[y + 1][x]
            && color === this.modules[y + 1][x + 1]
          ) {
            result += QrCode.PENALTY_N2
          }
        }
      }

      // Balance of dark and light modules
      let dark: int = 0
      for (const row of this.modules) {
        dark = row.reduce((sum, color) => sum + (color ? 1 : 0), dark)
      }
      const total: int = this.size * this.size // Note that size is odd, so dark/total != 1/2
      // Compute the smallest integer k >= 0 such that (45-5k)% <= dark/total <= (55+5k)%
      const k: int = Math.ceil(Math.abs(dark * 20 - total * 10) / total) - 1
      result += k * QrCode.PENALTY_N4
      return result
    }

    /* -- Private helper functions -- */

    // Returns an ascending list of positions of alignment patterns for this version number.
    // Each position is in the range [0,177), and are used on both the x and y axes.
    // This could be implemented as lookup table of 40 variable-length lists of integers.
    private getAlignmentPatternPositions(): int[] {
      if (this.version === 1) {
        return []
      }
      else {
        const numAlign: int = Math.floor(this.version / 7) + 2
        const step: int
          = this.version === 32
            ? 26
            : Math.ceil((this.version * 4 + 4) / (numAlign * 2 - 2)) * 2
        const result: int[] = [6]
        for (let pos = this.size - 7; result.length < numAlign; pos -= step) {
          result.splice(1, 0, pos)
        }
        return result
      }
    }

    // Returns the number of data bits that can be stored in a QR Code of the given version number, after
    // all function modules are excluded. This includes remainder bits, so it might not be a multiple of 8.
    // The result is in the range [208, 29648]. This could be implemented as a 40-entry lookup table.
    private static getNumRawDataModules(ver: int): int {
      if (ver < QrCode.MIN_VERSION || ver > QrCode.MAX_VERSION) {
        throw new RangeError('Version number out of range')
      }
      let result: int = (16 * ver + 128) * ver + 64
      if (ver >= 2) {
        const numAlign: int = Math.floor(ver / 7) + 2
        result -= (25 * numAlign - 10) * numAlign - 55
        if (ver >= 7) {
          result -= 36
        }
      }
      return result
    }

    // Returns the number of 8-bit data (i.e. not error correction) codewords contained in any
    // QR Code of the given version number and error correction level, with remainder bits discarded.
    // This stateless pure function could be implemented as a (40*4)-cell lookup table.
    private static getNumDataCodewords(ver: int, ecl: QrCode.Ecc): int {
      return (
        Math.floor(QrCode.getNumRawDataModules(ver) / 8)
        - QrCode.ECC_CODEWORDS_PER_BLOCK[ecl.ordinal][ver]
        * QrCode.NUM_ERROR_CORRECTION_BLOCKS[ecl.ordinal][ver]
      )
    }

    // Returns a Reed-Solomon ECC generator polynomial for the given degree. This could be
    // implemented as a lookup table over all possible parameter values, instead of as an algorithm.
    private static reedSolomonComputeDivisor(degree: int): byte[] {
      if (degree < 1 || degree > 255) {
        throw new RangeError('Degree out of range')
      }
      // Polynomial coefficients are stored from highest to lowest power, excluding the leading term which is always 1.
      // For example the polynomial x^3 + 255x^2 + 8x + 93 is stored as the uint8 array [255, 8, 93].
      const result: byte[] = []
      for (let i = 0; i < degree - 1; i++) {
        result.push(0)
      }
      result.push(1) // Start off with the monomial x^0

      // Compute the product polynomial (x - r^0) * (x - r^1) * (x - r^2) * ... * (x - r^{degree-1}),
      // and drop the highest monomial term which is always 1x^degree.
      // Note that r = 0x02, which is a generator element of this field GF(2^8/0x11D).
      let root = 1
      for (let i = 0; i < degree; i++) {
        // Multiply the current product by (x - r^i)
        for (let j = 0; j < result.length; j++) {
          result[j] = QrCode.reedSolomonMultiply(result[j], root)
          if (j + 1 < result.length) {
            result[j] ^= result[j + 1]
          }
        }
        root = QrCode.reedSolomonMultiply(root, 0x02)
      }
      return result
    }

    // Returns the Reed-Solomon error correction codeword for the given data and divisor polynomials.
    private static reedSolomonComputeRemainder(
      data: Readonly<byte[]>,
      divisor: Readonly<byte[]>
    ): byte[] {
      const result: byte[] = divisor.map(_ => 0)
      for (const b of data) {
        // Polynomial division
        const factor: byte = b ^ (result.shift() as byte)
        result.push(0)
        divisor.forEach(
          (coef, i) => (result[i] ^= QrCode.reedSolomonMultiply(coef, factor))
        )
      }
      return result
    }

    // Returns the product of the two given field elements modulo GF(2^8/0x11D). The arguments and result
    // are unsigned 8-bit integers. This could be implemented as a lookup table of 256*256 entries of uint8.
    private static reedSolomonMultiply(x: byte, y: byte): byte {
      if (x >>> 8 !== 0 || y >>> 8 !== 0) {
        throw new RangeError('Byte out of range')
      }
      // Russian peasant multiplication
      let z: int = 0
      for (let i = 7; i >= 0; i--) {
        z = (z << 1) ^ ((z >>> 7) * 0x11D)
        z ^= ((y >>> i) & 1) * x
      }
      return z
    }

    // Can only be called immediately after a light run is added, and
    // returns either 0, 1, or 2. A helper function for getPenaltyScore().
    private finderPenaltyCountPatterns(runHistory: Readonly<int[]>): int {
      const n: int = runHistory[1]
      const core: boolean
        = n > 0
        && runHistory[2] === n
        && runHistory[3] === n * 3
        && runHistory[4] === n
        && runHistory[5] === n
      return (
        (core && runHistory[0] >= n * 4 && runHistory[6] >= n ? 1 : 0)
        + (core && runHistory[6] >= n * 4 && runHistory[0] >= n ? 1 : 0)
      )
    }

    // Must be called at the end of a line (row or column) of modules. A helper function for getPenaltyScore().
    private finderPenaltyTerminateAndCount(
      currentRunColor: boolean,
      currentRunLength: int,
      runHistory: int[]
    ): int {
      if (currentRunColor) {
        // Terminate dark run
        this.finderPenaltyAddHistory(currentRunLength, runHistory)
        currentRunLength = 0
      }
      currentRunLength += this.size // Add light border to final run
      this.finderPenaltyAddHistory(currentRunLength, runHistory)
      return this.finderPenaltyCountPatterns(runHistory)
    }

    // Pushes the given value to the front and drops the last value. A helper function for getPenaltyScore().
    private finderPenaltyAddHistory(
      currentRunLength: int,
      runHistory: int[]
    ): void {
      if (runHistory[0] === 0) {
        currentRunLength += this.size
      } // Add light border to initial run
      runHistory.pop()
      runHistory.unshift(currentRunLength)
    }

    /* -- Constants and tables -- */

    // The minimum version number supported in the QR Code Model 2 standard.
    public static readonly MIN_VERSION: int = 1
    // The maximum version number supported in the QR Code Model 2 standard.
    public static readonly MAX_VERSION: int = 40

    // For use in getPenaltyScore(), when evaluating which mask is best.
    private static readonly PENALTY_N1: int = 3
    private static readonly PENALTY_N2: int = 3
    private static readonly PENALTY_N3: int = 40
    private static readonly PENALTY_N4: int = 10

    private static readonly ECC_CODEWORDS_PER_BLOCK: int[][] = [
      // Version: (note that index 0 is for padding, and is set to an illegal value)
      // 0,  1,  2,  3,  4,  5,  6,  7,  8,  9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40    Error correction level
      [
        -1,
        7,
        10,
        15,
        20,
        26,
        18,
        20,
        24,
        30,
        18,
        20,
        24,
        26,
        30,
        22,
        24,
        28,
        30,
        28,
        28,
        28,
        28,
        30,
        30,
        26,
        28,
        30,
        30,
        30,
        30,
        30,
        30,
        30,
        30,
        30,
        30,
        30,
        30,
        30,
        30
      ], // Low
      [
        -1,
        10,
        16,
        26,
        18,
        24,
        16,
        18,
        22,
        22,
        26,
        30,
        22,
        22,
        24,
        24,
        28,
        28,
        26,
        26,
        26,
        26,
        28,
        28,
        28,
        28,
        28,
        28,
        28,
        28,
        28,
        28,
        28,
        28,
        28,
        28,
        28,
        28,
        28,
        28,
        28
      ], // Medium
      [
        -1,
        13,
        22,
        18,
        26,
        18,
        24,
        18,
        22,
        20,
        24,
        28,
        26,
        24,
        20,
        30,
        24,
        28,
        28,
        26,
        30,
        28,
        30,
        30,
        30,
        30,
        28,
        30,
        30,
        30,
        30,
        30,
        30,
        30,
        30,
        30,
        30,
        30,
        30,
        30,
        30
      ], // Quartile
      [
        -1,
        17,
        28,
        22,
        16,
        22,
        28,
        26,
        26,
        24,
        28,
        24,
        28,
        22,
        24,
        24,
        30,
        28,
        28,
        26,
        28,
        30,
        24,
        30,
        30,
        30,
        30,
        30,
        30,
        30,
        30,
        30,
        30,
        30,
        30,
        30,
        30,
        30,
        30,
        30,
        30
      ] // High
    ]

    private static readonly NUM_ERROR_CORRECTION_BLOCKS: int[][] = [
      // Version: (note that index 0 is for padding, and is set to an illegal value)
      // 0, 1, 2, 3, 4, 5, 6, 7, 8, 9,10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40    Error correction level
      [
        -1,
        1,
        1,
        1,
        1,
        1,
        2,
        2,
        2,
        2,
        4,
        4,
        4,
        4,
        4,
        6,
        6,
        6,
        6,
        7,
        8,
        8,
        9,
        9,
        10,
        12,
        12,
        12,
        13,
        14,
        15,
        16,
        17,
        18,
        19,
        19,
        20,
        21,
        22,
        24,
        25
      ], // Low
      [
        -1,
        1,
        1,
        1,
        2,
        2,
        4,
        4,
        4,
        5,
        5,
        5,
        8,
        9,
        9,
        10,
        10,
        11,
        13,
        14,
        16,
        17,
        17,
        18,
        20,
        21,
        23,
        25,
        26,
        28,
        29,
        31,
        33,
        35,
        37,
        38,
        40,
        43,
        45,
        47,
        49
      ], // Medium
      [
        -1,
        1,
        1,
        2,
        2,
        4,
        4,
        6,
        6,
        8,
        8,
        8,
        10,
        12,
        16,
        12,
        17,
        16,
        18,
        21,
        20,
        23,
        23,
        25,
        27,
        29,
        34,
        34,
        35,
        38,
        40,
        43,
        45,
        48,
        51,
        53,
        56,
        59,
        62,
        65,
        68
      ], // Quartile
      [
        -1,
        1,
        1,
        2,
        4,
        4,
        4,
        5,
        6,
        8,
        8,
        11,
        11,
        16,
        16,
        18,
        16,
        19,
        21,
        25,
        25,
        25,
        34,
        30,
        32,
        35,
        37,
        40,
        42,
        45,
        48,
        51,
        54,
        57,
        60,
        63,
        66,
        70,
        74,
        77,
        81
      ] // High
    ]
  }

  // Appends the given number of low-order bits of the given value
  // to the given buffer. Requires 0 <= len <= 31 and 0 <= val < 2^len.
  function appendBits(val: int, len: int, bb: bit[]): void {
    if (len < 0 || len > 31 || val >>> len !== 0) {
      throw new RangeError('Value out of range')
    }
    for (
      let i = len - 1;
      i >= 0;
      i-- // Append bit by bit
    ) {
      bb.push((val >>> i) & 1)
    }
  }

  // Returns true iff the i'th bit of x is set to 1.
  function getBit(x: int, i: int): boolean {
    return ((x >>> i) & 1) !== 0
  }

  /* ---- Data segment class ---- */

  /*
   * A segment of character/binary/control data in a QR Code symbol.
   * Instances of this class are immutable.
   * The mid-level way to create a segment is to take the payload data
   * and call a static factory function such as QrSegment.makeNumeric().
   * The low-level way to create a segment is to custom-make the bit buffer
   * and call the QrSegment() constructor with appropriate values.
   * This segment class imposes no length restrictions, but QR Codes have restrictions.
   * Even in the most favorable conditions, a QR Code can only hold 7089 characters of data.
   * Any segment longer than this is meaningless for the purpose of generating QR Codes.
   */
  export class QrSegment {
    /* -- Static factory functions (mid level) -- */

    // Returns a segment representing the given binary data encoded in
    // byte mode. All input byte arrays are acceptable. Any text string
    // can be converted to UTF-8 bytes and encoded as a byte mode segment.
    public static makeBytes(data: Readonly<byte[]>): QrSegment {
      const bb: bit[] = []
      for (const b of data) {
        appendBits(b, 8, bb)
      }
      return new QrSegment(QrSegment.Mode.BYTE, data.length, bb)
    }

    // Returns a segment representing the given string of decimal digits encoded in numeric mode.
    public static makeNumeric(digits: string): QrSegment {
      if (!QrSegment.isNumeric(digits)) {
        throw new RangeError('String contains non-numeric characters')
      }
      const bb: bit[] = []
      for (let i = 0; i < digits.length;) {
        // Consume up to 3 digits per iteration
        const n: int = Math.min(digits.length - i, 3)
        appendBits(Number.parseInt(digits.substr(i, n), 10), n * 3 + 1, bb)
        i += n
      }
      return new QrSegment(QrSegment.Mode.NUMERIC, digits.length, bb)
    }

    // Returns a segment representing the given text string encoded in alphanumeric mode.
    // The characters allowed are: 0 to 9, A to Z (uppercase only), space,
    // dollar, percent, asterisk, plus, hyphen, period, slash, colon.
    public static makeAlphanumeric(text: string): QrSegment {
      if (!QrSegment.isAlphanumeric(text)) {
        throw new RangeError(
          'String contains unencodable characters in alphanumeric mode'
        )
      }
      const bb: bit[] = []
      let i: int
      for (i = 0; i + 2 <= text.length; i += 2) {
        // Process groups of 2
        let temp: int
          = QrSegment.ALPHANUMERIC_CHARSET.indexOf(text.charAt(i)) * 45
        temp += QrSegment.ALPHANUMERIC_CHARSET.indexOf(text.charAt(i + 1))
        appendBits(temp, 11, bb)
      }
      if (i < text.length) {
        // 1 character remaining
        appendBits(
          QrSegment.ALPHANUMERIC_CHARSET.indexOf(text.charAt(i)),
          6,
          bb
        )
      }
      return new QrSegment(QrSegment.Mode.ALPHANUMERIC, text.length, bb)
    }

    // Returns a new mutable list of zero or more segments to represent the given Unicode text string.
    // The result may use various segment modes and switch modes to optimize the length of the bit stream.
    public static makeSegments(text: string): QrSegment[] {
      // Select the most efficient segment encoding automatically
      if (text === '') {
        return []
      }
      else if (QrSegment.isNumeric(text)) {
        return [QrSegment.makeNumeric(text)]
      }
      else if (QrSegment.isAlphanumeric(text)) {
        return [QrSegment.makeAlphanumeric(text)]
      }
      else {
        return [QrSegment.makeBytes(QrSegment.toUtf8ByteArray(text))]
      }
    }

    // Returns a segment representing an Extended Channel Interpretation
    // (ECI) designator with the given assignment value.
    public static makeEci(assignVal: int): QrSegment {
      const bb: bit[] = []
      if (assignVal < 0) {
        throw new RangeError('ECI assignment value out of range')
      }
      else if (assignVal < 1 << 7) {
        appendBits(assignVal, 8, bb)
      }
      else if (assignVal < 1 << 14) {
        appendBits(0b10, 2, bb)
        appendBits(assignVal, 14, bb)
      }
      else if (assignVal < 1000000) {
        appendBits(0b110, 3, bb)
        appendBits(assignVal, 21, bb)
      }
      else {
        throw new RangeError('ECI assignment value out of range')
      }
      return new QrSegment(QrSegment.Mode.ECI, 0, bb)
    }

    // Tests whether the given string can be encoded as a segment in numeric mode.
    // A string is encodable iff each character is in the range 0 to 9.
    public static isNumeric(text: string): boolean {
      return QrSegment.NUMERIC_REGEX.test(text)
    }

    // Tests whether the given string can be encoded as a segment in alphanumeric mode.
    // A string is encodable iff each character is in the following set: 0 to 9, A to Z
    // (uppercase only), space, dollar, percent, asterisk, plus, hyphen, period, slash, colon.
    public static isAlphanumeric(text: string): boolean {
      return QrSegment.ALPHANUMERIC_REGEX.test(text)
    }

    /* -- Constructor (low level) and fields -- */

    // Creates a new QR Code segment with the given attributes and data.
    // The character count (numChars) must agree with the mode and the bit buffer length,
    // but the constraint isn't checked. The given bit buffer is cloned and stored.
    public constructor(
      // The mode indicator of this segment.
      public readonly mode: QrSegment.Mode,

      // The length of this segment's unencoded data. Measured in characters for
      // numeric/alphanumeric/kanji mode, bytes for byte mode, and 0 for ECI mode.
      // Always zero or positive. Not the same as the data's bit length.
      public readonly numChars: int,

      // The data bits of this segment. Accessed through getData().
      private readonly bitData: bit[]
    ) {
      if (numChars < 0) {
        throw new RangeError('Invalid argument')
      }
      this.bitData = bitData.slice() // Make defensive copy
    }

    /* -- Methods -- */

    // Returns a new copy of the data bits of this segment.
    public getData(): bit[] {
      return this.bitData.slice() // Make defensive copy
    }

    // (Package-private) Calculates and returns the number of bits needed to encode the given segments at
    // the given version. The result is infinity if a segment has too many characters to fit its length field.
    public static getTotalBits(
      segs: Readonly<QrSegment[]>,
      version: int
    ): number {
      let result: number = 0
      for (const seg of segs) {
        const ccbits: int = seg.mode.numCharCountBits(version)
        if (seg.numChars >= 1 << ccbits) {
          return Infinity
        } // The segment's length doesn't fit the field's bit width
        result += 4 + ccbits + seg.bitData.length
      }
      return result
    }

    // Returns a new array of bytes representing the given string encoded in UTF-8.
    private static toUtf8ByteArray(str: string): byte[] {
      str = encodeURI(str)
      const result: byte[] = []
      for (let i = 0; i < str.length; i++) {
        if (str.charAt(i) !== '%') {
          result.push(str.charCodeAt(i))
        }
        else {
          result.push(Number.parseInt(str.substr(i + 1, 2), 16))
          i += 2
        }
      }
      return result
    }

    /* -- Constants -- */

    // Describes precisely all strings that are encodable in numeric mode.
    private static readonly NUMERIC_REGEX: RegExp = /^[0-9]*$/

    // Describes precisely all strings that are encodable in alphanumeric mode.
    private static readonly ALPHANUMERIC_REGEX: RegExp = /^[A-Z0-9 $%*+./:-]*$/

    // The set of all legal characters in alphanumeric mode,
    // where each character value maps to the index in the string.
    private static readonly ALPHANUMERIC_CHARSET: string
      = '0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ $%*+-./:'
  }
}

/* ---- Public helper enumeration ---- */
namespace qrcodegen.QrCode {
  type int = number

  /*
   * The error correction level in a QR Code symbol. Immutable.
   */
  export class Ecc {
    /* -- Constants -- */

    public static readonly LOW = new Ecc(0, 1) // The QR Code can tolerate about  7% erroneous codewords
    public static readonly MEDIUM = new Ecc(1, 0) // The QR Code can tolerate about 15% erroneous codewords
    public static readonly QUARTILE = new Ecc(2, 3) // The QR Code can tolerate about 25% erroneous codewords
    public static readonly HIGH = new Ecc(3, 2) // The QR Code can tolerate about 30% erroneous codewords

    /* -- Constructor and fields -- */

    private constructor(
      // In the range 0 to 3 (unsigned 2-bit integer).
      public readonly ordinal: int,
      // (Package-private) In the range 0 to 3 (unsigned 2-bit integer).
      public readonly formatBits: int
    ) {}
  }
}

/* ---- Public helper enumeration ---- */
namespace qrcodegen.QrSegment {
  type int = number

  /*
   * Describes how a segment's data bits are interpreted. Immutable.
   */
  export class Mode {
    /* -- Constants -- */

    public static readonly NUMERIC = new Mode(0x1, [10, 12, 14])
    public static readonly ALPHANUMERIC = new Mode(0x2, [9, 11, 13])
    public static readonly BYTE = new Mode(0x4, [8, 16, 16])
    public static readonly KANJI = new Mode(0x8, [8, 10, 12])
    public static readonly ECI = new Mode(0x7, [0, 0, 0])

    /* -- Constructor and fields -- */

    private constructor(
      // The mode indicator bits, which is a uint4 value (range 0 to 15).
      public readonly modeBits: int,
      // Number of character count bits for three different version ranges.
      private readonly numBitsCharCount: [int, int, int]
    ) {}

    /* -- Method -- */

    // (Package-private) Returns the bit width of the character count field for a segment in
    // this mode in a QR Code at the given version number. The result is in the range [0, 16].
    public numCharCountBits(ver: int): int {
      return this.numBitsCharCount[Math.floor((ver + 7) / 17)]
    }
  }
}

export default qrcodegen
